Metallic tracer method for determining lubricant in engine exhaust



Sept 12,1961

RYAN

Filed June 2, 1960 OR DETERMINING SOMUM-REFERENCE QGNAL somuM REE fiGNAL mFFERENnAL SGNAL AMPUHER bNTEsRAToR1I TEsRAToR] Na CENTER somuM REFERENCE PHOTOMULTIPLIER PHOTOMULTI PLIER 5893A 6708A FILTER FILTER PHOTOMETER BURNER Q MRINLET GAS 333? SA ]NLET BY A7 METER Na RANGE FORD R BRYAN DVVENTUR.

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ATTORNEYS? United States atent Ford R. Bryan, Dearborn, Mich., assignor to Ford Motor Company, Dearborn, Mich., a corporation or Delaware Filed Juneo2, 1960, Ser. No; 33,516 8"Claims. (Cl.'73-'116) This invention teaches anovel useof thescience of flame photometry. This: application teaches especially the use of flame photometryto measure the insatntaneous oil consumption of an internal combustion engine.

I have discovered that many metallic constituents which may be present-in the lubricant of an internal combustion engine are substantially indestructible in the.combustion chamberand pass into the. exhaust streamin direct proportion to the: instantaneous .oil consumption of the engine. Flame photometry provides a convenient and highly sensitive-method of-measuring the low concentration of metal in such an exhaust-stream.

' To betterenablethis invention to be 'understood,-a single figure ofdrawing has been provided which is selfexplanatory. Aisampleof the exhaust gas-of the-engine to be tested is introducedintothe air supplyaof the photometer burner shown-at the lower left-hand corner of the drawing. The flame from this burneremits light exhibiting wave leng'ths-whichare characteristic of certain of the more easily excitable metals which maylbe incorporatedin the engine lubricant. The light from the burner is filtere'd' thr0ugh a filterconstructed to have a transmission peak -.at 5 893'Angstrom units. -'Another portion of this-light is led through a .filtenwhichiisvset .to have attransparency peak at any convenient valuewhich corresponds to no metal to' be'found in the exhaust stream. The particular filter shown has been constructed to peak at 6708 Angstrom units and corresponds to one of the frequencies which is characteristic of lithium which is absent from lubricating oils. The light from the 5893 Angstrom unit filter and that from the 6708 Angstrom unit filter is caused to fall upon respectively a sodium photo multiplier tube and a reference photo multiplier tube.

The output of the sodium photo multiplier tube and the output of the reference photo multiplier tube is passed through separate integrators and the output of the so dium photo multiplier is fed directly into a diflerential amplifier. The output of the reference integrator is fed to the diflerential amplifier through a potential arrangement. In this manner the output or the differential amplifier is a direct function of the ditference between the sodium signal and the reference signal. The output of the differential amplifier is read directly upon the meter at the right-hand side of the drawing.

While it is obvious that many metals can be incorporated in the lubricating oil to instantaneously measure the lubricating oil consumption, sodium has been found to be very satisfactory because of the intensity of the light amplification by the sodium flame. It is preferred to incorporate the sodium in the lubricating oil in the form of an oil soluble sodium compound and specifically the sodium soap of mahogany acids has been found excellent for this purpose. Mahogany acids are sulfonic acids of unknown chemical constitution which are obtained by the initial treatment of crude petroleum with strong sulphuric acid as one of the first steps in refining the crude petroleum. The sodium mahoganates are obtained therefrom by a simple neutralization by a soluble alkali such as sodium hydroxide or sodium carbonate.

As a specific example of this invention, the following experimentation was performed with a Briggs and Stratton single cylinder 4-cycle engine having a horepower PatentedSept. 12, 1961 rating of'2'.25 maximum at 3600 r.p.m. The piston displacement was 6.65 cubic inches and the crankcase capacity 1.25- pints. The engine was operated during these tests on a non-leaded gasoline. Suflicient sodium mahogany soap was added to the crankcase lubricant to give a concentration of 0.43 percent sodium in the lubricant. Tests were made at various speeds from 1000 r.p.m. to over 3000 r.p.m. with the'engine in the condition in which it was received from the factory and with the-rings-modified to progressively increase the oil consumption of the engine.

The engine as received when operating at 3000 r.p.m. upon an oil. containing 0.48 percent sodium consumed 18 grams of oil perv hour and gave a reading of 9 divisions upon the meter. The engine modified to consume 21 grams of oil per hour gave a reading of I 10 /2 divisions. Further modification of the engine to increase the oil. consumption to 40 grams per hour gave a reading of 23 divisions. Thus it can be seen that there is a subs'tantially linear relationship between oil consumption and'the meter reading. The time lag is only that which can be attributed to" the sampling apparatus and aver aged about 2 seconds. Inthe case of an automobile enginewhich uses on the average of 1 gram of oil per -minute,;consumption can be estimated with an accuracy of. plus or minus five. percent.

.1 claim:

l.-*The processtof determining the substantially instantaneous lubricant consumption of aninternal combustion enginewhich comprises establishing in the lubricant ofthe: internal'combustion engine a known concern .tration. ofametallic' compound which is soluble in the lubricant, operating-the engine, abstracting from the exhaust stream of the engine a samplewhich constitutes a knownniraction of the totalexhaust-stream, entraining this sample in a flame and photometrically determining the intensity of the light generated by the flame and having a wave length Which is characteristic of the metal introduced into the lubricant by the metallic compound, said light intensity being indicative of the substantially instantaneous lubricant consumption.

2. The process of determining the substantially instantaneous lubricant consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a known concentration of a sodium compound which is soluble in the lubricant, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, entraining this sample in a flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic of the sodium introduced into the lubricant by the sodium compound, said light intensity being indicative of the substantially instantaneous lubricant consumption.

3. The process of determining the substantially instantaneous lubricant; consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a known concentration of sodium mahogany soap, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, entraining this sample in a flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic of the sodium introduced into the lubricant by the sodium mahogany soap, said light intensity being indicative of the substantially instantaneous lubricant consumption.

4. The process of determining the substantially in stantaneous lubricant consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a concentration of sodium of about 0.48 percent in the form of sodium mahogany soap, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust streamgene training this sample in a flame and photometrically determining the intensity of light generated by the flame and having a wave length which is characteristic ofthe sodium introduced into the lubricant by the sodium mahogany soap, said light intensity being indicative of the substantially instantaneous lubricant consumption.

5. The process of determining, the substantially instantaneous lubricant consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a known'concentration of a metallic compound which is soluble in the lubricant, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, incorporating this sample in a stream of air, employing this air stream to support a gas flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic of the metal introduced into the lubricant by the metallic compound, said light intensity being indicative of the substantially instantaneous lubricant consumption.

6. The process of determining the substantially instantaneous lubricant consumption. of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a known concentration of a sodiumcompound which is soluble in the lubricant, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, incorporating this sample in a stream of air, employing this air stream to support a gas flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic of the sodium introduced into the lubricant by the sodium compound, said light intensity being indicative of the substantially instantaneous lubricant consumption.

7. The process of determining the substantially instantaneous lubricant consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a known concentration of sodium mahogany soap, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, incorporating this sample in a stream of air, employing this air'stream to support a gas flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic of the sodium introduced into the lubricant by the sodium mahogany soap, said light intensity being indicative of the substantially instantaneous lubricant consumption.

8. The process of determining the substantially instantaneous lubricant consumption of an internal combustion engine which comprises establishing in the lubricant of the internal combustion engine a concentration of sodium of about 0.48 percent in the form of sodium mahogany soap, operating the engine, abstracting from the exhaust stream of the engine a sample which constitutes a known fraction of the total exhaust stream, incorporating this sample in a stream of air, employing this air stream to support a gas flame and photometrically determining the intensity of the light generated by the flame and having a wave length which is characteristic .of the sodium introduced into the lubricant by the sodium mahogany soap, said light intensity being indicative of the substantially instantaneous lubricant consumption.

References Cited in the file of this patent UNITED STATES PATENTS 1,729,732 Wasson Oct. 1, 1929 2,664,779 White Ian. 5, 1954 

